Pivoting workpiece supports are utilized in a number of manufacturing environments to provide a variable orientable work surface for the assembly of components such as printed circuit assemblies, computer hard drives, automotive components, etc.
With a pivoting workpiece support, a platform is pivotably supported on a base, with a rotational coupling utilized to secure the platform support to the base. An adjustment mechanism may also be coupled to the workpiece support to permit an operator to adjust the relative angle of the platform.
One benefit of a pivoting workpiece support is the fact that the platform can be adjusted for use with different operators, or may be adjusted by a single operator to optimize the orientation of the platform for different tasks. In addition, a pivoting platform may also be used to permit multiple sides of a workpiece to be accessed at a comfortable orientation for an operator.
To maximize an operator's productivity when using a workpiece support, it is desirable for the adjustment mechanism to be as fast and easy to operate as possible. Also, given that an operator can exert significant torque while working on a platform, it is also desirable for an adjustment mechanism to be secure and reliable to minimize unwanted movements of the platform.
Conventional adjustment mechanisms such as set screws have been used to selectively lock a platform in a desired rotational orientation for extended periods of time. With a set screw, a threaded screw is oriented perpendicular to a pivot shaft for radial movement relative to the axis of rotation of the pivot shaft. Rotation of the threaded screw applies a force through the end of the screw to the pivot shaft to restrict rotation of the pivot shaft about its axis of rotation.
One problem with set screws and the like is that they are often difficult to manipulate in a fast and efficient manner. Some set screws may require several turns both to release and re-secure the pivot shaft. In addition, the force required to twist a set screw may induce fatigue in an operator, particularly if the operator makes frequent adjustments. As a consequence, set screws are not typically used in environments where repetitive adjustments are required.
One conventional adjustment mechanism utilized in some pivoting workpiece supports is a pawl and ratchet design, where a toothed wheel coupled to a pivot shaft is engaged by a pawl to selectively permit or restrict rotation of the pivot shaft. Other mechanisms utilize a spring-loaded shot pin configured to engage in one of a plurality of holes disposed circumferentially around a shaft. Conventional pawl and ratchet designs and shot pin designs, however, are not infinitely adjustable, and are restricted by the number of teeth disposed on the ratchet or holes disposed on a shaft. Such designs may also be slow and cumbersome, and may require significant effort to operate.
Therefore, a significant need continues to exist in the art for a fast and efficient adjustment mechanism for use with pivoting workpiece supports and the like.